Bacteriophage λ N Protein Disorder‐Order Transitions upon Interactions with RNA or Proteins

Structural Disorder in Viral Proteins

“…Structurally, λN is characterized by all the features typical of highly disordered proteins, starting from high net charge and low hydrophobicity and ending with structural asymmetry as determined by sedimentation and gel filtration experiments, the coil-like far-UV CD spectrum, , and a narrow chemical shift dispersion in the NMR spectra . Later, detailed SAXS analysis revealed that the radius of gyration of native λN is 38 ± 3.5 Å and its fractal dimension 1.76 ± 0.05, exceeding the value predicted for a well-solvated polymer with excluded volume (1.7) .…”

“…The major in vivo λN function is to serve as a transcriptional antitermination factor that binds to a specific RNA sequence (the box B segment) and multiple proteins in the transcription complex, thereby serving as the key regulator of the assembly of the antitermination complex, which allows transcription through termination sites during gene expression of the phage. λN also interacts with a bacterial host factor (NusA) and the RNA polymerase of the bacterial host …”